LANSING (AP) – Many of Michigan’s tea party activists are trying to coalesce behind one of the eight Republicans running for the chance to unseat Democratic U.S. Sen. Debbie Stabenow, but the infighting over whether a unified effort is the way to go could harm GOP chances to deny Stabenow a third term.

The movement is patterned on successful efforts by Indiana tea party groups that have rallied behind Richard Mourdock as the tea party challenger to Republican U.S. Sen. Richard Lugar. In Michigan, more than 50 tea party groups have joined under the name Michigan 4 Conservative Senate, or MI4CS for short, to try to avoid dispersing their clout in a field crowded with conservatives.

The group is sponsoring a Senate debate Saturday at Central Michigan University and plans to return to the Mount Pleasant campus on Feb. 25 to hold a straw poll and decide which candidate will get the group’s backing leading up to the August GOP primary.

“Anybody can win the straw poll. … It’s very much wide open,” said Cindy Gamrat, a spokeswoman for MI4CS and Plainwell Patriots leader. “We hope this gives the tea party a chance to get their voice heard in a national Senate election.”

The idea of acting like a political party isn’t sitting well with some tea party groups, however.

Joan Fabiano, head of Grassroots in Michigan, isn’t participating in the push to unite behind one candidate. She backs Detroit charter school executive Clark Durant, but her reluctance to coalesce behind one candidate is less about who gets picked than about the process.

“To me, the tea party movement is a movement and a philosophy,” she said. “(Political) parties have conventions; movements don’t. … I don’t think it helps the tea party movement in Michigan as a whole.”

The candidates participating in Saturday’s debate are Durant, former Kent County Judge Randy Hekman, Scotty Boman of Detroit, Brighton businessman Chuck Marino and Gary Glenn of Midland, president of the American Family Association of Michigan. Gamrat expects about 100 people to attend the two-hour debate. It also will be streamed live online on the Patriot Voice Radio Network.

It’s the last official MI4CS event before the Feb. 25 straw poll, when about 100 people – two from each tea party group – will cast their votes. The fact that large tea party groups get the same two votes as much smaller ones has caused some to pull out of the process.

A few of the Senate candidates aren’t enthused about the idea, either. Front-runner Pete Hoekstra isn’t participating in Saturday’s debate, and neither is Roscommon businessman Peter Konetchy or Rick Wilson of Grand Blanc.

“Why would we want to start the politicization of the Tea Party Movement and drown out the voices of those members who do not support the `Tea Party candidate’?” Konetchy said in statement. “Tea parties have educated their members and encouraged individual activism. … Our job is to educate the people about our strengths and our core values, and then allow the people to nominate Stabenow’s opponent. That is the purpose of the primary.”

Some Hoekstra supporters say the effort is being pushed by his rivals to deny him the nomination. The Holland Republican hasn’t endeared himself to tea party activists or other conservatives by skipping Saturday’s debate.

“Unfortunately, Mr. Hoekstra decided making his case to members of the next generation – many of whom never voted before and were eagerly looking forward to participating in their first election this year – wasn’t a priority,” Campus Conservatives, which is co-sponsoring the debate, said in a Friday statement.

Hoekstra, who served in Congress for 18 years before unsuccessfully running for governor last year, has been tagged by fellow GOP Senate candidates and their supporters as not conservative enough. They’ve criticized his votes for the Troubled Asset Relief Program that bailed out banks and for raising the federal debt limit, among other issues.

“He’s aware that he’s probably not a tea party favorite because he’s had some votes that certainly would not line up with the tea party philosophy of limited government,” Fabiano said.

People are wondering “will that candidate bring my voice to the U.S. Senate if they’re not listening now,” said Gamrat. “Leaders have been reaching out to him, but for his own reasons he’s choosing not to participate in various tea party functions.”

Hoekstra campaign spokesman Paul Ciaramitaro disputed that assessment, noting that the candidate has attended many tea party events and plans to attend more.

“Pete Hoekstra has traveled across the state meeting voters from all walks of life and engaging in countless conversations about instilling fiscal responsibility in Washington. He has already participated in over 20 tea party forums, meetings and town halls this campaign and looks forward to growing that number as he puts together a wide-ranging coalition to defeat Debbie Stabenow,” Ciaramitaro told The Associated Press.

Gamrat denies that much of the push for a unified vote is coming from Glenn supporters, as some tea party groups leery of the effort claim.

Glenn was instrumental in getting a constitutional amendment passed by Michigan voters in 2004 defining marriage as a union between a man and a woman, effectively banning the legal recognition of same-sex marriage. He’s also involved in a federal lawsuit brought by three Michigan ministers who say a federal hate crime law infringes on their First Amendment rights and should be declared unconstitutional.

Glenn is working hard to win the MI4CS nomination, as is Durant. Both hope to weaken Hoekstra’s ties to tea party activists.

Gamrat said MI4CS isn’t out to force any group that thinks picking one candidate is a bad idea to participate.

“I totally respect their opinion about that. This has always been voluntary,” she said. “But we also ask them to respect the groups who do want to do this.”